1. Field of the Invention
The invention concerns a safety device for a pyrotechnic impact fuse of a ballistic high explosive shell comprising a pyrotechnically reactive material which is initiated upon impact, whereby a ball safety device only passes into an armed position after the launch of the shell. A central initiation passage is arranged in a penetration passage of a valve body and is provided with a ball guide with spaced end abutments for a ball mounted therein, and including lateral firing passages which open into the central initiation passage behind the ball in the armed position of the ball safety device.
2. Discussion of the Prior Art
A safety device of that kind for a pyrotechnic percussion or impact fuse is known from DE 195 44 458.2-21. A pyrotechnic material which is fired upon impact is disposed in the ogive of the shell. The internal space in the shell is connected to the space in which the pyrotechnic material is disposed, by way of a central firing passage. Lateral firing passages open into the firing passage. The central firing passage is also intended to accommodate a ball. The function of this arrangement is to afford bore safety, in other words, while the shell is passing through the barrel, any firing of the pyrotechnic material is sealed off by the ball in the firing passage so that the explosive charge in the interior of the shell body cannot be fired.
The object of the invention is to enhance the operational reliability of the ball safety device.
The greater degree of functional reliability of the ball safety device is afforded by the spring element which acts on the ball. The spring element ensures that the ball is seated in the safe position in a condition of being displaced back in the direction of the base, in a simple manner. In that situation the ball seals off the central firing passage at the periphery thereof. It has surprisingly been found that any firing gases or vapours which possibly pass around the ball are stopped or rendered harmless by the spring element to such an extent that the subsequently arranged boosting charge is not fired. Any firing gases or vapours experience multiple reduction due to the spring element which is also in a condition of contact therearound and are in part deflected in a centripetal direction where they are mutually reduced or nullified in respect of their energy.